Am I able to claim the American Opportunity Tax Credit if I had gone to school for more than 4 years, but never have claimed the AOTC before?

Some back story: I've been going to  school for a while--6 in community college on & off, and 2-3 yrs in a university.  I just recently obtained my Bachelors in June of 2020.

 

Here's the thing, I have never filed taxes because I have been considered a non-filer all these years.

However, even though I am still considered a non-filer, I was  filing my taxes for 2020 and noticed that I was eligible for the American Opportunity Tax Credit that I was never aware of, so I continued on with the filing without claiming it because I didn't know if I was able to. 

 

Fast forward to now: I'm amending my tax return again for several reasons, and I was wondering , is it still possible to claim it somehow even though I have never claimed this credit throughout all these years?

 

One person responded to a similar question in which he said that I was able to claim it for 2020 assuming I was half time or more, or not have claimed in the past.  And that I am still able to amend the 2018/2019 tax returns to claim the previous years.

 

I just get confused and assume I'm unable too because  it asks how many years of college have I completed since Jan 2020, and clearly it's been more than 4 years. When I choose that option--4yrs (5th yr senior) , I'm unable to claim the educational credit. But if I were to choose the option before--3yrs (senior) I am able too. 

 

So am I able to claim this credit in my amended tax return , at least for 2020 or not? If so, do I choose the 3yrs (senior) option in order to get the credit?

 

Thank you.